Checkered Garter Snake
Thamnophis marcianus • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Thamnophis, Species: T. marcianus
Found in southwestern United States (including Texas, New Mexico, Arizona, Oklahoma), extending southward through much of Mexico and into Central America.
Look up Checkered Garter Snake in the Snake Encyclopedia →Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Thamnophis, Species: T. marcianus
Conservation
IUCN Red List status is Least Concern, due to its wide distribution, tolerance of disturbed habitats, and generally stable population trends.
Physical Description
Displays a distinct checkered pattern of dark blotches on a lighter olive, gray, or brown background. A pale vertebral stripe is usually present running down the length of the back, flanked by lighter lateral stripes on the sides. Head is distinct from the neck with rounded snout, and scales are typically keeled.
Size & Dimensions
Specimens generally range from 40 to 90 cm (16 to 35 inches) in total length. Adult size.
Habitat
Typically found near water sources such as streams, ponds, marshes, and irrigation canals, but also adapts well to arid and semi-arid environments, grasslands, and agricultural areas.
Diet & Feeding
Diet consists primarily of amphibians (frogs, tadpoles, toads), small fish, and occasionally earthworms or small rodents. Active foragers that rely on keen senses of smell and tongue-flicking to locate prey.
Reproduction
Viviparous (live-bearing), producing litters ranging from 5 to upwards of 20 or more young during the summer months. Mating typically occurs in the spring after emerging from brumation.
Look-alikes
Frequently confused with other garter snake species (Thamnophis spp.) and ribbon snakes. Distinguished by the specific checkerboard pattern of alternating dark spots and the exact placement of the lateral stripes.
Conservation Status
IUCN Red List status is Least Concern, due to its wide distribution, tolerance of disturbed habitats, and generally stable population trends.
Cultural Significance
Plays an important ecological role in controlling amphibian and invertebrate populations in aquatic and riparian ecosystems. Often encountered by humans near suburban water features.
Notable Features
Known for high adaptability to urban and agricultural runoff environments, allowing them to thrive in regions where natural wetlands have been heavily modified.